Materials are known that are suitable for presenting a special crystal structure in which the atoms become preferentially arranged in atomically thin plane structures or “lamellae” within which the atoms are strongly bonded together, while weaker bonds act between the atoms of two adjacent lamellae. Such lamellae may present thicknesses of one or a few monatomic layers.
Various materials, e.g. semiconductor materials such as InSe or GaS, and metallic materials, possibly superconductors, such as graphite, NbSe2, TaS2, or MgB2, are suitable for presenting a lamellar structure. With reference more particularly to graphene, methods are known for mechanically separating lamellae, which methods consist either in cleaving or scraping a piece of graphite, or in applying an adhesive tape to a piece of graphite and tearing it off. It is then necessary to use an optical microscope to search for any graphene lamellae that might have become detached from the piece of graphite. In order to handle or process these graphene lamellae, and in particular to order to prevent them rolling up, it is then appropriate to fasten the lamellae on a substrate, e.g. using resin, and that is found to be difficult. Those methods are poorly reproducible and are not suitable for mass production.